ISX Coolant Pressure...Videos

If you have no air build problems I would say what your seeing is normal. May sound or look weird coming from the intake depending on if the compressor is charging or unloaded. Remember, the air compressor is just a mini engine with no combustion, when unloaded the "valves are open" so the air has to go somewhere.

 

Still the original compressor on your truck?

 

If it was my truck..... i would replace it.
It has done it's time.

 

Goodysnap beat me to it on that looking more like a compressor issue, not a head issue. If you had huge bubbles, I would be concerned of the head, bu those are tiny and more in line to compressor. EGR cooler is gone so that is ruled out.

Remove the coolant lines and tee them together on your compressor then recheck.

Also on what daf105paccar mentioned. That is quite a bit of hours on your compressor... I'm surprised the unloader isn't leaking with that many hours on it.

 

You know you can rebuild the compressor.

It's a small engine i.e. piston/head/gaskets etc

or simply swap it out

 

I have never had success with the fluid test for combustion and don' t trust the test results, period ,no matter the engine. Your bottle test is accurate if done correctly. Run the engine up to temp with the surge tank fill cap off. If you are checking while running up to temp you can get some false bubbles due to temp expansion as the coolant temp increases and the fluid expands. Run your hose from the fill cap to your bottle. Run the engine through the rpm range and watch for continuous bubbles. Hold it at max rpm and snap throttle repeatedly to see if anything changes in the consistency. No bubbles means its not currently leaking. Watch closely when the compressor is building vs unloaded. Not always, but if it is indeed the compressor the bubbles will lessen when unloaded or after the dryer purges.